The present invention relates to the art of making snow for ski resorts and the like. More particularly, it relates to further improvements in automation of the snow-making process.
Though the art of snow-making has been practiced for several decades, it is still a labor-intensive process to produce a large quantity of "quality" snow at a desired location on a mountain side. While it is now a relatively simple matter to combine compressed air and water in a "snow-gun" to produce, under controlled conditions, a uniform blanket of snow having a desired moisture content, it is considerably more difficult to produce such a blanket of snow on a ski trail atop a mountain where the terrain is highly irregular, and the temperature, relative humidity and wind undergo frequent, unpredictable and severe changes of the type that dramatically affect snow quality and placement. It is not uncommon, for example, to discover in the morning following a night of snow-making that, as a result of an unexpected change in humidity, temperature and/or wind speed or direction, most of the snow made has either been deposited into the adjacent woods, or has become so laden with moisture as to become unsuitable for skiing.
To cope with the ever-changing weather conditions, many ski resorts maintain large crews of equipment operators whose primary function is to make weather-related adjustments to the snow-guns. For example, the guns should always be aimed in a direction to take wind direction and speed into account. Moreover, the compressed air-to-water ratio should always be maintained at a level which accounts for both ambient temperature and relative humidity; otherwise the snow consistency will be either too wet or too dry. Only a few degrees temperature change, or a few percent change in relative humidity, will have a dramatic effect on the snow-making efficiency and quality of the snow produced.
In the commonly assigned U.S. Pat. No. 5,031,832 issued in the names of H. R. Ratnik et al., there is disclosed a snow-making system in which the tasks of aiming the snow-gun and adjusting the air-to-water ratio are performed remotely. Motor-controlled valves are used to adjust air and water flow to the guns, and motor-controlled mounts are used to adjust both azimuth and elevation of the snow spray. While this automated system allows adjustments to be made from afar, there is still a need for an operator to make frequent visits to each snow gun site to adjust for changes in temperature and/or humidity.
While it is known in the art to use a centrally located computer to adjust the air-to-water ratio at each of a plurality of snow-gun sites based on temperature and relative humidity samplings at each site, such centrally-controlled systems tend to be disadvantageous from the standpoints of cost, complexity and maintenance. For example, in the case of a computer failure, snow-making over the entire ski resort is affected. Moreover, there is no easy way to override a nominal air-to-water setting to compensate for changes in system parameters, such as variations in water temperature, compressed air pressure, water purity, etc. In such case, an equipment operator located at an affected snow-gun site must communicate with the central control station, identifying the site of interest and ordering changes, for example, in water flow rate to cure the problem observed. Achieving the desired flow rate through an intermediary is not a trivial task. Moreover, as indicated above, any maintenance or servicing of the computer system also has the effect of shutting down the entire snow-making operation.